What is an EPROM

An EPROM, acronym for Erasable Programmable Read Only Memory, is a read only erasable memory through ultraviolet rays. It has evolved from the PROM which, once programmed, could not be modified. EPROM can be completely erased for a limited but consistent number of times and reprogrammed.

The writing in the memory cell of the EPROM is realized through a breakdown phenomenon. An electrical tension is created between the PINS of the EPROM until the device is programmed in each of its sections. In general, EPROM manufacturers furnish the data related to the programming, such as the PIN through which the programming should be done and the type of tension to be used.

An EEPROM, acronym for Electrically Erasable and Programmable Read Only Memory, is a user programmable ROM memory. Writing, erasing and reprogramming operations are performed electrically. Each individual memory cell capable of memorizing a single bit is made up of two MOS transistors, a “memory” and an “access” one. The EEPROM technology was developed on the basis of the preexisting EPROM technology in order to prevent the cancellation of the data. In the EPROM system, in fact, while the writing can be done electrically, the cancellation can be done only through the UV radiation exposure, with relative inconveniences of logistic nature, such as the removal of the chip from the card on which it is assembled, with relative time loss. The technology of the EEPROM, which can be erased electrically, has permitted, in several cases, to erase and reprogram that component without having to take it apart from the electronic cell. Very often, it is possible to erase and reprogram only certain sectors of the EEPROM, operation which was not possible with the EPROM.

EEPROMS are the most common electronic component using quantum mechanics. A flash memory is a permanently rewriteable memory organized in blocs, that is to say a semiconductor circuit on which it is possible to store data in binary form and retain it in absence of any electrical supply. Being an electronic circuit, it does not use any mobile parts and thus, it is particularly resistant to strain and chocks and in addition, it is extremely small and light. This type of portable memory is particularly indicated for its transportability, as it does not require any electrical supply to retain its data and because it requires little space; indeed it is much used in digital cameras, portable music readers, cellular phones, pendrives, personal digital assistants, modern portable PC, cars electronic units, motorcycles electronic units and in many other devices requiring a high portability and a good memory capacity to safeguard the data.